As one example of a rotation detection sensor, Japanese Laid-Open Patent Publication No. 2004-198305 discloses a rotation detection sensor applied to a hub unit of a vehicle. The hub unit includes an external cylinder and an internal cylinder. The external cylinder is fixed to a body of the vehicle. The internal cylinder, which rotates together with a vehicle wheel, is arranged inside the external cylinder. A rotor, which is cylindrical and has a flange, is fixed to the internal cylinder. The flange of the internal cylinder is magnetized in a manner that its north pole and its south pole are positioned alternately along its circumferential direction. The rotation detection sensor for detecting the rotation speed of the rotor (that is, the rotation speed of the vehicle wheel) is arranged on the external cylinder.
The rotation detection sensor includes a cover member for closing an end portion of the external cylinder. A connector having a connector terminal and a Hall device is attached to the cover member. The connector terminal is integrated with the connector through insert molding and electrically connected to the Hall device of the connector. The connector is connected to the cover member in a manner that the Hall device faces the flange of the rotor.
As a method for manufacturing the rotation detection sensor, the connector having the Hall device is first set in a mounting hole formed in the cover member. In a state set on the cover member, the connector is arranged in a mold to perform resin molding. The resin surrounding the Hall device is solidified to integrate the connector and the cover member. This completes the rotation detection sensor.